The present invention relates to management and control of communication networks and, in particular, to management and control of communication networks via policies and over a network.
Networks
A communication network typically includes a number of network devices that, among other functions, transmit or receive data. A local area network, commonly referred to as a LAN, is a privately owned network that facilitates communication among the devices coupled to the network via one of several data communication protocols such as Ethernet or FDDI. Multiple LANs are typically interconnected via, for example, private links or satellite transmissions to form a wide area network, commonly referred to as a WAN. Such LANs and WANs are increasingly being interconnected through the internet.
Communication network systems are becoming ever more complex. To increase resource sharing and facilitate their supervision, computer systems, such as facsimile machines, desktop computers, printers, etc. are typically coupled to a LAN. The complexity that arises as a result of increasing the number and the variety of systems, which in the aggregate form a computer network, coupled with the variety of communication protocols that such devices are required to support, increase the knowledge base that is often required to manage such networks. The problem is further compounded by the increasing complexity of new generation of high performance network devices and their interoperability as well as by the lack of qualified and well-trained network administrators. To operate and conform to a network's objectives, a network device (e.g. a router) is first configured—i.e., the networking parameters of the device are set to desired values. An inventory as well as a record of the configuration parameters of each configured networked device is typically maintained for future reference. Network devices are often reconfigured (e.g., by changing router ports, routing tables, IP addresses) to accommodate for network expansion or modification—for example, to add a new user to the network.
Device Based Network Management
One conventional method of configuring a networked device is to issue commands which are specific to the device via a computer system. A drawback of this method is that each networked device is configured and subsequently verified separately to ensure its conformity with the desired network objectives. Another drawback of this method is that it requires an extensive knowledge base—of the various network device types—which may become prohibitively large as the number of device types in a network rises.
Outsourcing Network Management
Another known method for managing a communications network is through outsourcing the network management to another commercial entity. For example, WorldCom Inc., located at 500 Clinton Center Drive, Clinton Miss., 39056 offers a network management service based on which a group of network administrators at WorldCom, upon receiving specific requests to manage or configure a network device, transmit related commands and data via the internet to the network device thereby to manage or configure the device. The method, however, involves human intervention and is thus inefficient and unautomated.
Policy-Based Network Management
A third known method for managing networked devices is to include a number of individual devices of a given type in a policy domain and apply a set of policies to the domain. Such policy-based methods, however, are only applicable to a limited number of specific device types. Furthermore, in such conventional policy-based network communication systems, policies are defined through a descriptive programming language. The applied policies so defined become attributes of their associated devices and are thus not objects which can be pointed to and thus viewed.
In directory-enabled policy-based network management systems, a directory serves as the central location for storing policies, profiles, user information, network configuration data, and internet protocol (IP) infrastructure data, such as network addresses and server information. Policies in directory-enabled networking (DEN) are defined in terms of rules containing conditions and actions for managing users, network resources, and services/applications.
In DEN, physical details of a network are separated from the logical attributes of the application types. DEN has many key attributes and characteristics that typically enable an associated network to be rapidly reconfigured and operate with other platforms. A directory-enabled network is typically scalable, fault-tolerant, and, preferably recognizes people and application by their associated attributes and characteristics and not by their numerical sequences, such as their IP addresses.
Data stored in the directory of a directory-enabled network are typically in formats derived from standard schemas based on the DEN specification published by a group of companies which are collectively known as the Distributed Management Task Force (DMTF). A schema is a collection of rules defining the relationships among objects representing users, applications, network elements, and network services. Each schema contains rules which govern the organization and logical representation of the schema objects.
Access to a directory in DEN is commonly governed by version 3 of the lightweight directory access protocol (LDAPv3), which is a stripped down version of X.500 directory services standard. LDAP is used for bulk loading policies into a directory.
In a directory-enabled network, network entities and the relationship between such network entities are governed by an information system, known in the art as the common information model (CIM). A CIM contains rules regarding management of, for example, hardware, operating systems, operations, application installation and configuration, security, identity, etc. The CIM, which is also defined by the DMTF, is a standard object-oriented model that represents objects in terms of instances, properties, relationships, classes and subclasses. A primary goal of the CIM is to present a consistent view of managed networks independent of the protocols and data formats supported by the various devices in and applications running on the networks.
One known directory serving as the central storage location in a directory-enabled network is the Windows 2000 Active Directory™, which is developed by and is available from Microsoft Corporation located at One Microsoft Way, Redmond, Wash., 98052. In addition to serving as the central policy store, Windows 2000 Active Directory™ provides a framework for, among other functions, publishing network services, managing users, computer systems, applications and services, as well as secure intranet and internet network services. Furthermore, Windows 2000 Active Directory™ provides a backbone for distributed security in Windows 2000 and a central service point for administrators to manage network services. Windows 2000 Active Directory™, which is an effective platform for DEN, is based on standard protocols such as Domain Name System (DNS)—which is used to locate servers running Active Directory—LDAPv3 (described briefly above) and Kerberos—which is a security protocol for logon authentication.
The Windows 2000 Active Directory™ includes a schema with definitions for every object class that exists in the directory service. Therefore, the universe of objects that may be represented in the Active Directory™ is extensible. Other information related to the Windows 2000 Active Directory™ features and functions are available from Microsoft corporation. The Active Directory supports Component Object Model (COM) features. COM is a language independent standard that promotes object oriented programming by specifying the interfaces of a component at the binary level.
As stated above, conventional methods of configuring and maintaining a communication network are costly, time-consuming and require expert administrators capable of reliably managing and controlling ever more complex network systems in a timely manner.